Answer by
worker6862 (30)
A normal uterus has 3 layers - endometrium, myometrium and perimetrium. Of these endometrium lines inside and is covered by lining epithelium of cuboidal to columnar cells. During the different phases of menstrual cycle,the lining undergoes series of changes. A thick uterus lining indicates the thickening of the endometrium which is more common in the secretory phase of menstrual cycle.